Practice question

Partial digestion generates a nested set of subpopulations where some sites are cut and others remain intact. For a linear end-labeled molecule with three internal sites, cleavage can stop after the first site, after the second, after the third, or include all three, producing fragments that extend from the labeled end to each site successively. With n sites, the number of distinct labeled species equals n+1. For three sites, four labeled fragments of increasing length appear on autoradiography, while internal unlabeled fragments remain invisible, enabling ordered map construction.